Floor covering



2 Sheets-Sheet l L. L. LARSON ET AL FLOOR COVERING Filed March 20, 1935J B! kN M N Jan. 18, 1938.

m Y m m v mw 0 N w. W w? 0 lflmfi V Jan. 18, 1938. 1.. LARSON El ALFLOOR COVERING Filed March 20, 1935 2 Sheets-Sheet 2 aww GearyelATTORNEY.

Patented Jan. 18, 1938 UNITED STATES 2,105,484 FLOOR covaamc LouisLeonard Larson and George Lewis Schwartz, Wilmington, Del., assignors toKrafelt Corporation of America, Wilmington, DeL, a corporation ofDelaware Application March 20, 1935, Serial No. 12,110

7 Claims.

This invention relates to floor covering, and more particularly to animproved process for producing smooth surface floor coverings carryingthe coloring or pattern substantially through the sheet.

Floor coverings of the type described herein have previously been madeby decorating a fibrous material with a coloring visible on at least oneface thereof and extending well down into the body ofv the sheet and tining the fibers but not filling the voids between the fibers, drying thesheet thus decorated, filling the voids with a transparent saturantfilling material, and finally a surfacing coat of lacquer or varnish maybe applied. In accordance with the present invention, an improvement inboth process and product is effected by saturating the sheet from theface to a considerable extent before printing, this process involvingthe special procedure and materials more fully described hereinafter.

This invention has as its object process and product improvements in themanufacture of a smooth surface floor covering having the color orpattern visible on the surface and extending substantially through thesheet. A further object is to reduce to a minimum the number of stepsrequired for the production of a floor covering of this type. A furtherobject is the production in a continuous operation of a filled sheethaving a pattern extending well through the sheet. A further object is aprocess in which a printed and filled sheet is obtained at the curingstage and in which additional application of saturant after the curingstage is not required. A further object is to provide productimprovements through mechanical treatments of the surface during thefinishing operation. A still further object is to provide a, processutilizing improved compositions which permit the production in acontinuous operation of a substantially filled sheet having a patternextending well through the sheet and which impart to the product theproperties that are required in a smooth surface floor covering. Otherobjects will appear hereinafter.

In the preferred method of carrying out our process the following stepsare included: (1) the sheet is partially saturated from the face to anextent of about 50% with a definite amount of selected pigmented varnishcomposition; (2) the sheet is printed in pattern or in solid color bythe application to its face of a definite amount of print paint which.penetrates substantially through the sheet; (3) the printed sheet iscompletely' saturated from the back with a selected pigmented varnishcomposition; (4) the printed and saturated sheet is pulled into afestoon or curing rack. These steps constitute a continuous operation.Where furtherfinishing is desired the remaining operations may consistin sanding the completely cured sheet to obtain a smooth even surfaceand finishing with a thin coat of suitable finishing composition, orfinishing may consist in pressing the partially cured sheet to obtain asmooth even surface and then completing the cure, or in pressing thecured sheet, and if desired a thin coat of a suitable finishing materialmay be applied for the purpose of appearance.

The steps involved in the manufacture of our improved floor coveringsfrom a fabric base, saturating and printing compositions, etc., alllater described in detail, will be better understood by reference to thediagrammatic views of the accompanying drawings in which Fig. 1 is aview in elevation of an assembly for performing the saturating, printingand curing steps of the first operation;

Fig. 2 is an elevational view of sanding mech anism; 1

Fig. 3 is an elevational view of mechanism used for waxing.

The numeral I designates a supply roll of absorbent sheet material fromwhich the strip of sheet material indicated by the numeral 2 passes overroller 3, under rollers 4 and 5 and over roller 6. saturant is appliedto the face of the sheet material by a transfer roll I contacting thesheet material and dipping into the saturant 8 which is heated to about120-130 F. contained 3 in the pan 9. The transfer roll I is equippedwith a doctor knife Ia. The sheet material then passes between s'queezerolls III and II, over rollers I2 and I3 and over adjustable rolls I5and I6. The short loop I4 formed in the sheet material between rolls I3and I5 permits continual operation of the face saturating step at aspeed equal to the average forward movement of the sheet on the printingmechanism. The printing of the sheet material on the same face to whichthe saturant was applied takes place between the rollers l5 and I6.

The mechanism for applying the print paint may be the well known feltbase printing machine of conventional construction which includes asuitable support for the sheet material between rollers I5 and I6, thisprinting mechanism being shown but diagrammatically in the drawings. Theprinting ink is applied to the print block I! by means of a roller I8dipping into the printing ink contained .in the receptacle l9 carried bycog wheels riding in racks 20a which are disposed parallel to the sheetmaterial and spaced somewhat from its edges. As the receptaclecontaining the print paint is moved either manually or mechanically tocontact the roller IS with the face of the print block II, the cogwheels cause rotation of the roller l8 by means of suitable connectingmechanism not shown. After application of the print paint to the printblock I! the latter is lowered in the usual way by mechanism formingpart of the printing machine to contact its inked face against the sheetmaterial 2, and the forward movement of the sheet material isinterrupted during contact of the print block with the sheet material.

After the sheet material is printed, rolls 22 and 23 pull it over amiddle roll 24 which transfers saturating composition from thereceptacle 24a to the back of the sheet material, that is, to the sideopposite to which the saturant 8 and the print paint were applied. Thenumeral 25 designates a doctor knife for removing excess saturant whichis collected by a drip pan 26. The material heat, ventilators, anddrying racks. The curing may also be efiected by a drying-chamber of thefestoon type. The product thus cured at a temperature of approximately150 F. fora period of several days is then passed over a roll 3| and iswound into a roll 32. q

The mechanism for sanding is shown in Fig. 2 where the printed andsaturated material unwinds from roll 33 over a revolving drum 33a andunder pull rolls 34 and under sanding rolls 35. The sanding rolls areprovided with hoods 35 from which abrasive loosened from the rolls 35 isdrawn by suction. The numeral 31 indicates a roll brush provided with ahood 38 similar to the ones over the sanding rolls. The sheet materialpasses under the last pull roll 34 and is wound into a roll 39.

The product after the sanding step may be finished with a thin coat ofwax, lacquer, varnish, or any other suitable finishing composition. Whena wax finish is used the preferred method is to apply two coats by a hotmelt application with a transfer roll. The first coat is applied to thesheet while it is heated above the melting point of the wax which causesthe wax to impregnate the fine pores in the surface. The secondapplication of wax coats the surface and for this purpose it is appliedafter it has cooled below the melting point of the wax. In these waxingsteps the sanded material may pass directly to the waxing machine or, asshown in Fig. 3, it may unroil from a supply roll 40 over carrying roll4|, and under carrying rolls 42 and over carrying roll 43 adjacent towhich the wax is applied to the printed surface of the sheet from a waxroll 44. The roll 44 bears against a roll 45 which dips in wax containedin receptacle 46, and as the rolls 44 and 45 revolve with the movementof the sheet material the wax is transferred from the receptacle to thesheet material. The numeral 41 inproduce an operating viscosity.

end by a pressing operation. An advantage of thepressing operation overthe sanding operation is that it tends to solidify the sheet. The bestresults are obtained by pressing the sheet at a stage of partial cure.In this form of the invention we prefer to cure the sheet forapproximately 24-36 hours, press, and thencomplete the cure in a festoonor straight rack. For plate pressing the best conditions are 1200 poundsper square inch pressure, a pressing period of about 15 seconds and apressing temperature of about C. The sheet should be preheated before itenters the plate press. After the sheet has been pressed and completelycured, a thin coat of wax, varnish,

or lacquer may be applied.

In addition to solidifying the sheet and producing a smooth surface,pressing eliminates the tendency possessed by unpressed sheets to curlupwards at the edges. Another method of preventing edge curl that may beused in connection with a sanding operation is boarding the sheet byflexing it sharply over a roll about 1 inch in diameter. A suitableapparatus consists of a small roll about 1 inch in diameter supported bytwo larger rolls about 6 inches in diameter. The sheet passes under thefirst supporting roll, sharply over the small roll, and under the secondsupporting roll. The sheet is pulled through this boarding machine, andthe supporting rolls may be driven.

' Several factors have a fundamental influence on the successfuloperation of the above process. Saturant'should be applied only from theface before the printing operation in order to obtain the mostsatisfactory penetration of the print paints and working properties ofthe sheet on the print machine. The operation of the face saturant at anelevated temperature substantially decreases the amount of solventrequired to It is of great importance in this process of producing asubstantially filled sheet in a continuous operation that the solventcontent of all filling materials should be held to a minimum. Bycontinuous operation we mean that the sheet from a roll of porous feltin a continuous band is threaded through the entire system of machineryfor performing the step of applying saturant to the face, applying printpaint to the face, applying additional saturant to the back, anddelivering the filled sheet into the drying chamber. Each of these stepsis performed in their regular sequence without rewinding the sheet intoa roll which would smear the pattern. The application of saturant fromthe back after printing completely fills the sheet by raising the levelof the still liquid paint and improves the brightness of colors on theface without impairing the definition of design. Thus the production ofa substantially filled sheet carrying a well defined pattern wellthrough it in a continuous operation depends upon introducing part ofthe saturant before printing and part of the saturant after printing. Inthe surfacing operation, the composition of the materials must be suchthat the sheet will sand easily without gumming the sandpaper. If thesheet is plate pressed this should be done for best results at a stageof partial cure while the saturants and paints are still somewhatthermoplastic. The

compositions and properties of the saturants and print paints-and theamounts of each have a fundamental influence upon the operation of theprocess and the quality of the finished product. A discussion ofmaterials follows:

The saturating base is a porous, absorbent, continuous sheet. The widthof the sheet is regulated to the width of the print machine, and theprinted area is commonly two or three yards wide with an extra inch ormore on each side for the bands that carry the sheet over the printmachine.

The saturating base should have an absorptive capacity and porosity asdefined respectively by a kerosene absorption of around 260% to 320% anda porosity on the Gurley densometer of around 1.8 to 2.2 seconds for asheet approximately 0.049" thick. The kerosene absorption is measured'by the standard A. S. T. M. method for roofing felts. The porositygiven. is the seconds required for the displacement of 400 cc. of airthrough a 3 ply thickness of the sheet on a Gurley densometer. Thereference to kerosene absorption and porosity in this specification isin terms of these definitions. A saturating base which meets the abovepreferred requirements is the absorbent and porous sheet formed fromartifically crinkled fibers by the process described in United StatesPatent 1,857,100.

The saturant applied before printing may contain only neutraloressentially non-coloring pigment such as calcium carbonate, or it mayalso contain colored pigments.

We prefer to use as the face saturant a pigmented varnish comprisingpigment, drying oils, resins, oxidation inhibitor, driers, and solvent.In formulating the varnish, the types and proportions of the drying oilsare important. The use of linseed oil or its equivalentadds solubilityto the varnish and flexibility to the dried film. China-wood oil impartsrapid drying characteristics, strength, hardness, dryness,waterproofness, moisture-proofness, and grease-proofness. We prefer touse an amount of China-wood oil equal to about 50% to 80% of the totalweight of drying oil. We have found that the resin content of thevarnish has a pronounced influence on the quality of the productespecially in regard to wearing and cleaning properties. We prefer touse a varnish the non-volatile content of which consists of about 17% to34% of resin. Also, we prefer to use a resin that is fairly alkali andgrease resistant, such, for example, as Amberol, cumar, hydrocarbonresins, or rosin modified glyceryl phthalate and similar polyhydricalcohol-polybasic acid resins. A varnish of low body should be usedbecause the body of the varnish is the controlling factor in the amountof solvent required to cut the face saturant to a working viscosity. Itis of fundamental importance that the solvent content of the facesaturant should be held to a minimum because an object of the process isto produce a substantially filled product in a single continuousoperation. Also the use of excessive amounts of solvent increases costand fire hazards. The preferred body of the varnish defined in terms ofviscosity is from 3 to poises at 77 F. for a 90% solution in mineralspirits.

The incorporation of pigment into the saturant lowers the materialscost, decreases drying time, and improves the quality of the finishedproduct such as sanding properties, cleanability, resistance toexpansion and to indentation, and wearing properties. A pigment shouldbe selected 'cosity is from 1.4 to 3.0 poises.

which when dispersed in the varnish will not filter to any appreciableextent on the surface during the face saturating operation prior toprinting. We prefer a pigment that has low covering power.Certain-calcium carbonate pigments and certain clays have been found tomeet. the requirements. The proportion of pigment to non-volatilevehicle in the face saturant should be fairly high. We prefer that thenon-volatile content of the face saturant should consist of 40% to 60%by weight of pigment.

The viscosity of the face saturant should be as high as possibleconsistent with satisfactory penetrating properties. The preferredoperating vis- The face saturant should not contain more than about 35%by volume of solvent, and the preferred amount is 25% or less by volume.

An oxidation inhibitor of the phenolic ether type such as creosol,guaiacol, eugenol, or vanil lic acid is incorporated into the saturantin order to eliminate fire hazard through spontaneous combustion duringthe early stages of the curing operation. The amount of inhibitor shouldbe approximately 0.8% by weight based on nonvolatile binder.

The print paints serve to fill the sheet as well as to impart a patternsubstantially through it, so they have an important influence on thequality of the finished product, especially in regard to cleanability,In order to obtain the maximum filling of the sheet, it is importantthat the solvent content of the paint should be as low as possibleconsistent with satisfactory penetrating properties. Also, the paintshould be formu- 5 China-wood oil contents is the tendency of the Ipaint to skin on the print blocks. However, the addition of an oxidationinhibitor to the paint permits the use of a China-wod oil content ashigh as or more of the total oil.

The paint should contain sufficient pigment to have good covering power,brightness and depth of color, and satisfactory hardness, dryness,cleanability, and resistance to expansion through changes in atomspherichumidities. These properties are best obtained by using a high pigment Icontent. We prefer to use a paint that contains about or parts by weightof covering pigment to 45 or 40 parts by weight, respectively, ofnon-volatile vehicle.

The viscosity of the paint should be as high as possible consistent withsatisfactory printing properties. The object is to hold the solventcontent of the paint to a minimum, and obtain a finished productsubstantially free from large pores. A viscosity around 2.0 poises hasbeen found to give excellent results although the process is not limitedto this viscosity. The print paints should contain not more than about20% by volume of solvent, and the preferred amount is 15% or less byvolume.

We prefer to use as the back saturant a pigmented varnish consisting ofpigments, drying oils, resins, driers, oxidation inhibitor, and solvent.We have found it desirable to use in the back saturant a high proportionof pigment such o the same as that used in the face saturant.

as 60 parts of pigment to 40 parts of non-volatile binder. The pigmentmay be a low cost filling pigment, such as gilders whiting, China clay,as= bestine, talc, etc. The binder may be essentially As in the facesaturant and print paints, the amount of solvent should be held to aminimum. We have found that a good operating viscosity is around 4poises. The back saturant should contaln not more than about 30% byvolume of solvent, and the preferred amount is 20% or less.

The amounts of the above-described face saturant, print paint, and backsaturant have a fundamental influence on the operation of the processand the quality of the finished product. If

the amount of face saturant is too low. the print 1 paints'do notpenetrate satisfactorily, andiftoo high the print paints floodexcessively" and run on the surface. The preferred amount of saturantapplied before printing is the amount that will occupy from 45 to 55% byvolume of the saturating capacity of the sheet. The minimum amountshould not be less than 35% and the maximum amount not be much more than10% by volume of the saturating capacity of the sheet. The saturatingcapacity may be determined by measuring the volume of kerosene absorbedby a unit weight of the sheet. The amount of print paint should besufficient so that (1) the pattern extends well into the sheet, (2) thecolors of the pattern are bright and strong, and (3) the product is wellfilled. We prefer that the print paints should occupy 20 to 30% byvolume of the initial saturating capacity of the sheet, although theprocess is not limited to this range. The back saturant should then fillthe sheet so that to of the saturating capacity is occupied by thefilling materials at this stage in the process, and if desired an excessof saturant may be left on the back as a coating. In the event that thesaturant applied before printing and the print paints occupy 95% or moreof the initial saturating capacity of the sheet, the application of backsaturant may be omitted, although in the preferred operation of theprocess back saturant will occupy 20 to 35% of the initial saturatingcapacity of the sheet.

The degree of filling of the finished product should be above a certainminimum value in order that the product will have satisfactorycleanability, resistance to indentation and expansion, wearingqualities, etc. The degree of filling may be expressed by thenon-fibrous to fibrous ratio of the product. This ratio for material ofabout 0.045" and greater thicknesses should not be less than 2.75 to 1.0by weight, and we prefer that it.

Example I The base is an absorbent sheet formed on a paper machine, suchas a Fourdrinier, from a furnish consisting of a artificially crinkledand bleached kraft fibers, starch (for strengthening purposes), rosinsize, and alum. The artificially crinkled fibers are prepared by theprocess of the above mentioned patent U. S. 1,857,100. For this purpose,the best crinkling results are obtained by wetting kraft pulp with an18% solution of sodium hydroxide at about 25 C., at a fiber consistencyof about 20%, and promptly washing the fibers until neutral. .Followingthis, the pulp is bleached with a suitable bleach such as calciumhypochlorite, and again washed. The crinkled and bleached pulp isthencharged into a beater and treated with swollen corn starch(approximately 10% based on the fiber weight), rosin size, and alum. Thetreated .pulp is then diluted to a suitable paper making consistency andformed into a sheet on a Fourdrinier paper machine by modified regularprocedures.

An absorbent sheet suitable for this process may have the followingpropertiesi Weight lbs. per sq. yd 0.66 Thickness inches 0.049 Keroseneabsorption per cent 300 Porosity (Gurley densometer, 400 cc.displacement of air through 3 plies of sheet) seconds 2.0 Mullenbursting strength pounds 40.0 Color (Ives tintphotometer) 165 Theabsorbent base is converted into a floor covering as follows:

The sheet is partially saturated from the wire side (the side next tothe forming wire during the manufacture of the base) by application bymeans of the roll 1 of 1.31 lbs. per square yard of saturant Ahereinafter described. The saturant is usually heated (-130 F.). tern isthen printed into the sheet from the wire side by the application of0.66 lbs. per square yard of print paint B. After being printed, thesheet passes off the printing machine and over the back saturatingmechanism shown in the drawing where 0.51 lbs. per square yard ofsaturant B is applied at the temperature of the print room, which forbest results should be approximately 80-90 F. The sheets cut to properlength are then pulled into the drying chamber and cured about four daysat 150 F.

Following the curing operation, the product is finished by sanding andwaxing the surface by mechanisms of the kind shown in the drawing.

The surface is sanded with a fine sand paper such as 2/0 fiint paper,until smooth and even. Approximately 0.5% by weight of the sheet isremoved in sanding to a smooth surface. A wax coating (0.03lbs. persquare yard) is applied to the surface as a hot melt by the transferroll method. A suitable wax composition consists of 82.5 parts ofcarnauba and 17.5 parts of a -130 F. melting paraflin.

The finished product weighs 2.77 lbs. per square yard, and its thicknessis 0.049". Its non-fibrous to fibrous ratio is 3.2:1.0 by weight. Thepattern extends approximately 70% through the sheet, and it ischaracterized by brightness of color and excellent definition of design.The product has excellent wearing properties and a smooth surface ismaintained with wear. The surface has good initial cleanability and itcontinues to clean well with wear. The initial pliability and permanenceof initial pliability are very satisfactory. For example, the stiffness(at 25 C. 50% relative humidity) measured by the Smith-Taber stiffnesstester with the 2,000 unit weight on the pendulum is 21 in the machinedirection and 14 across the sheet, and these The patvalues increase only25% after four weeks of aging at 150 F.

Example II An absorbent sheet as described under Example I was partiallysaturated from the wire side with 1.05 lbs. per square yard of saturantA thinned 5% by weight with mineral spirits, printed on the wire sidewith 0.75lbs. per square yard of print paints, and saturated from theback with 0.62 lbs. per square yard of saturant B, by the proceduregiven under Example I with the exception that the saturant bath wasoperated at the temperature of the print room (80-90 F.)

instead of 120130 F.

The sheet was then pulled into a festoon and cured for 30 hours at 150F. It was then plate pressed to produce a smooth and even surface and tosolidify the sheet. The conditions for plate pressing were a pressure of1200 lbs. per square inch, 15 seconds at pressure, and a pressingtemperature of 280 F., the sheet being preheated before it entered thepress by passing it over a hot plate.

Following the pressing operation, the cure was completed by'stoving thesheet in a festoon for 60 hours at 150 F. Finally, the surface wasfinished with a thin coat of lacquer (0.03 lbs. per

I Example III An absorbent sheet as described under Example I waspartially saturated from the wire side with 1.30 lbs. per square yard ofsaturant printed with 0.66 lbs. per square yard of print paints, andcompletely saturated from the back with 0.60 lbs. per square yard ofsaturant C by the procedure given under Example I. The sheet was curedfor days at 150 F., following which it was finished by the proceduregiven under Example I.

The finished product weighs 2.93 lbs. per square yard, and its thicknessis 0.049. Its non-fibrous to fibrous ratio is 3.44:1.0 by weight. Theproduct wears well and cleans well with wear.

Example IV In this example, a thicker sheet was processed in a solidcolor. The properties of the sheet are: a weight of 0.73 lbs. per squareyard, a. thickness of 0.057", a kerosene absorption of 305%, a Mullenbursting strength of 47 lbs., and a porosity as defined above of 3.1seconds. The sheet was partially saturated from the wire side with 1.50lbs. per square yard of saturant "Af thinned 5% by weight with mineralspirits. The saturant was applied by the' transfer-roll method, and thebath of saturant was operated at 80-90 F. The sheet was then printed onthe wire side with 1.02 lbs. per square yard of print paint. Twoimpressions of paint were applied to the sheet, the second impressionregistering directly over the first impression. This was done by usingtwo print blocks to carry paint to the sheet. Each print block is cut togive a solid coverage of paint over the entire surface. The first blockapplied 0.62 lbs. per square yard of print paint B, and the second blockapplied 0.40 lbs. per square yard of print paint A. Following theprinting operation, the sheet passed from the print machine and wassaturated from the back by the application of 0.50 lbs. per square yardof. saturant B. The sheet was then cured and finished as under ExampleI.

The finished product weighs 3.32 lbs. per square yard, and its thicknessis 0.059". Its non-fibrous to fibrous ratio is 3.55: 1.0 by weight. Theproduct has excellent wearing and cleaning properties.

Example V An absorbent base which was formed from cotton linters pulpand which has a thickness of 0.049", a weight of 0.64 lbs. per squareyard, a kerosene absorption of 278% and a porosity of 2.9 seconds, wasconverted into a. fioor covering as follows: The sheet was partiallysaturated from the wire side with 1.01 lbs. per square yard of saturantA, printed on the wire side with 0.75 lbs. per square yard of printpaint B, and completely saturated from the back with 0.40 lbs. persquare yard of saturant B, cured, and finished in accordance with theprocedure given under Example I.

The finished product weights 2.69 lbs. per square yard and itsnon-fibrous to fibrous ratio is 3.2:1.0 by weight.

Example VI An absorbent base which had been formed from a highlypurified bleached sulphite wood pulp Y of high alpha cellulose contentand which had a thickness of 0.047", a weight of 0.46 lbs. per squareyard, a kerosene absorption of 419%, and a porosity (as defined underExample I) of 3.8 seconds, was converted into floor covering as follows:The sheet was partially saturated from the felt side with 1.02 lbs. persquare yard of saturant A, printed on the felt side with 0.76 lbs. persquare yard of print paint B, and completely saturated from the backwith 0.43 lbs. per square yard of saturant B, cured, and finished inaccordance with the procedure given under Example I.

The finished product weighs 2.5 lbs. per square yard, and itsnon-fibrous to fibrous ratio is 4.4:1.0 by weight.

The compositions of the saturants and print paints in the above examplesare as follows:

Mineral spirits 4.5 Creosol 0.32 Mineral spirits 14.18

The above ingredients are ground in a pebble mill for approximately 20hours.

The saturant has a viscosity of 4.5 poises at 77 F. This viscosity willvary somewhat from batch to batch.

Varnish A, which is a constituent of this saturant, is prepared asfollows: 100 parts of a rosin modified phenolic resin (such as BS-lAmberol), 769.3 parts of China-wood oil, and 77.8 parts of varnishmakers alkali-refined linseed oil are run to 525 F. The kettleis thenremoved from the fire and 100 parts of French rosin (combined fusedreslnates of lead and calcium) and 1.25 parts of manganese resinate areadded. When these have fused, 115 parts of a heat bodied alkali-:reflnedlinseed oil (body of S on the Gardner-Holdt scale) is added. Finally,

131 parts of mineral spirits and 2.8 parts of a lead-manganese liquiddrier (4.77% lead. 1.42 manganese) are added. The above amounts are inparts by weight. The varnish is strained while hot. The varnish has aviscosity of Z-lil bubble at 77 F. on the Gardner-Holdt scale.

. saturant B Mill base (roller mill grind) Parts by Weight Pigment (suchas gilders whiting) 57.40 Varnish A" Resins, drying oils, and driers38.34 6o Mineral spirits 4.26 Formulation of saturant Mill base 84.10Creosol. 0.36 Mineral spirits 15.54

The saturant has a viscosity of 3.60 poises at 77 F.

saturant "C" Parts by weight Pigment (such as precipitated calciumcarbonate treated with a wetting agent)--- 43.60 Varnish A Resins,drying oils, and driers 21.8 20

Mineral spirits 2.4 Varnish B I Resins, drying oils, and driers--- 21.82o

Mineral spirits 2.4 Creosol'. 0.17 Mineral spirits 7.83

. are added. After the temperature has dropped to 450 F., 131 parts ofmineral spirits and 2.8 parts of lead-manganese liquid. drier (4.77%lead, 1.42% manganese) are added. The amounts given above are in partsby weight. The varnish is strained while hot.

Varnish B has a viscosity of G at 77 F. on the Gardner-Holdt scale. I

Print paint "A" Plgments Parts by weight White pigment (such aslithopone treated with a wetting agent) 53.60 Tinting pigment (such aschrome 55.20 yellow) 1.60

Varnish B Resins, drying oils, and driers 36.72} 8o Mineral spirits 4.08Mineral spiri 4.00

A thorough dispersion of the pigments in the vehicle is obtained byroller mill or pebble mill grinding.

The paint has a viscosity of 4.0 poises at 77 F. A more practicalprocedure for preparing the paint is to make individual grinds of thepigments with the vehicle, and then tintthe white paint with the coloredpaint.

Print paint "8 Parts by weight 'Print paint A" 100.0 Varnish 3" 9.2Mineral spirits 2.0

and absorbency. The kerosene absorption of the sheet may vary some fromthe preferred range given above. It may be as low as 250% and it may behigher than 320%. The process is not limited to any special thickness ofsheet, although the most practical thickness is around 0.050"i15%, butwide variationsfrom this value may be used in practicing the invention.

Numerous changes in the process described above may be made withoutdeparting from the scope of this invention. The sheet, for instance,'maybe treated throughout with saturant prior to printing, providing duecare is taken so that the pores in the back of the sheet are not sealedwith saturant and the amount of saturant placed in the sheet beforeprinting falls within the limits previously prescribed herein. This maybe accomplished by impregnating the sheet by immersion in saturant suchas saturant A thinned 5% by weight with mineral spirits, and

thenpassing the sheet between squeeze rolls to ad paint the printmachine may be replaced by a machine having a transfer roll and squeezerolls such as the machine described for application of saturant to theface prior to printing. Another procedure particularly applicable forsolid color floor covering is to fill 60 to 70% by volume of thesaturating capacity of the sheet with saturant, such as saturant A forexample, by the impregnation and squeezing process given above, andprint in solid color with one or more applications of paint to the face.The amount of paint applied is sufficient to fill the remaining 30 to40% byvolume of the initial saturating capacity of the sheet. After thepaint is applied the sheet is pressed by applying a mash block to theface on the print machine. This causes the paint to penetrate the sheet.so that all of the pores in the sheet are filled. The treated sheet isthen cured and finished by procedures previously described herein.

Another variation that may be suggested consists in partially saturatingthe sheet with a strengthening composition such as varnish or lacquerbefore the sheet is processed as described above. A special back coatmay be applied to the sheet after it has been processed and cured. Thespecial back coat improves waterproofness, moisture-proofness,resistance to expansion, and resistance to curl at the edges. Suitablecompositions for back coating are waxes, wax-resin compositions,varnishes, paints, lacquers, rubber compositions, etc. 7

In the formulation of the saturantawe prefer to use a pigmented varnishbecause the introduction of pigment lowers materials cost, decreasescuring time, and substantially improves quality. The amount of pigmentmay be varied over wide limits. In the face saturant, the pigface of thesheet.

pigments as used in the paints.

, given above.

ment should not filter appreciably on the sur- Any pigment which has theproper dispersing properties and penetrating properties when ground withthe vehicle, and which does not impair the colors of the print paintsmay be used.

A certain amount of a strong covering pigment, such for example aslithopone, may be used in the face saturant in order to improve thebrightness of color of the light colored print paints. For example,.lithopone may constitute to of the pigment content of the face saturant.A colored back may be produced by adding tinting colors (coloredpigments ground in the vehicle) to the back saturant. Also in producinga solid color product the saturant may contain the same The resincontent and the types'and proportionsof drying oils of the saturants andprint pa nts may also be varied within rather wide limits. Forsatisfactoryresults the resin content should not be lower than 10% normuch higher than 40% by Weight of the non-volatile content of thevarnish. The pigment content of the saturants may be decreased as theresin content of the varnish is increased. Any drying oil or combinationof drying oils may be used with the resin that will give a varnish ofsatisfactory working properties and satisfactory product quality.Numerous drying oils may be used as a substitute for linseed oil, suchas soya bean oil, pcrilla oil, and menhaden oil. Softeners such asprocessed corn oil, tricresyl phosphate, and chlorinated wax may be usedin amounts up to 10% of binder.

Likewise, in the formulation of the print paints. any pigment orcombination of pigments that has satisfactory working properties in theprocess may be used. In floor covering print paints, the white pigmentsand filling pigments generally ,in the process, such as Prussian blue,ultrarnarine blue, carbon black, cchers, sienna, red ox de, chromegreens, chrome yellows. etc. In p actice the paints are prepared bygrinding individual pigments with the vehicle and then tinting whitepaint with colored paints to give the various colors desired.

The process is not limited to the operating temperatures for thesaturants and print paints For example, the saturan-s may be operated athigher temperatures than 120-130 F., and the print paints may beoperated at temperatures higher than the temperature of the print roomby heating the paints in the carriages.

A modification of our process utilizing the materials described above isthe production of a sheet which, although not completely filled at thecuring stage as in the preferred method, contains a substantial portionof the saturatingmaterials at the curing stage. The sheet is then filledby saturating after partial or complete cure with a suitablecomposition. The steps in this modified process comprise, therefore,partially saturating the saturating base from the face with an amount ofsaturant somewhat less, especially in non-volatile constituents, thanmentioned in the foregoing examples (about preferred, but not less than35%, of the saturating capacity), printing a pattern into'the sheet withprint paints, applying saturant from the back, partially curing thesheet, completing the saturation of the sheet-from the face or byimmersion with a suitable saturant, continuing the cure until ready forpressing, pressing to produce a smooth and even surface, completing thecure, and finally finishing the surface with a thin coat of a suitablefinishing material. The following example illustrates this process:

Example VII An absorbent sheet 0.057" in thickness, weighlng 0.77 lbs.per square yard and having a kerosene absorption of 310% is processed bythe modified method mentioned above as follows: 1.3 lbs. per square yardof saturant A thinned 7% by weight with. mineral spirits is applied tothe felt side of the sheet by the transfer roll method. The

sheet is then printed on the felt side with 1.3 lbs.

per square yard of print paints correspond ng to Print Paint B thinned7% by weight with min- This amount of paint is applied by eral spirits.two impressions of each color on the sheet, so that two blocks areprovided in the print machine for each color making up the pattern.Following this 0.35 lbs. per square yard of saturant "A thinned 7% byweight with mineral spirits is appled to the back by the transfer rollmethod. The sheet is then pulled into a festoon and cured 6 hours at 150F., following which it is removed from the festoon and saturated fromthe face side by the application of 0.16 lbs. per square yard ofsaturant "A. The sheet is then returned to the festoon and cured for 10hours at 150 F.

It is then removed from the festoon and plate pressed. The pressingconditions are a pressure of 1200 lbs. per square inch, 9. temperature 1of 270 F, and 15 seconds at pressure. The sheet is preheated before itenters the press by passing over a hot plate. Following'the pressingoperation, the cure is completed by stoving for 68 hours at 150 F.Finally, a thin finishing coat of lacquer is applied (0.03 lbs. persquare yard of lacquer solids The product in the above example has afinished weight of 3.45 lbs. per square yard and a thickness of 0.05ratio is 3.67:1.0. The product has exceptionally good wearing andcleaning properties.

Numerous compositions may be used for the final filling of the sheet.softened pyroxylin is of particular value in this application in that itimparts unusually good cleaning properties and also it improves theresistance of the product against changes in dimension through changesin atmospheric humidities. A suitable softened pyroxylin composition mayconsist of 13.9 parts of second cellulose nitrate, 11.1 parts of castoroil, and parts of solvent. such as ethyl cellulose, clear varnishes,certain waxes such as carnauba wax or hydrogenated vegetable oils,rubber compositions, vinyl resins,

phenolic resins, etc., may be used.

In the modified process it is not necessary to apply saturant to theback after printing because the printed sheet is again impregnated tonearly complete saturation after it has been partially The non-fibrousto fibrous Other compositions cured. Saturants and print paints used.during the printing operation may contain more volatile (not more than10% by weight more than limits prescribed for solvent content ofsaturants and print paints in the operation of preferred process) whendesigned for this modified process in order that there will besuflicient residual porosity to permit good impregnation with the finalsaturant. However, the volatile contents should not be much greater thanin the above example or the print paints will run and thus ruin thedefinition of design.

An important and distinguishing feature of our invention is thesaturating of the sheet in substantial amount before printing. Theminimum amount of saturant applied should not bemuch less than 35% byvolume of the saturating capacity of the sheet and it should not besubstantially more than 70%. In the case of the preferred process wherethe sheet is completely filled or substantialy so with or without backsaturation, the face saturant is applied before the printing step inamounts of from 35% to 70%. In the modified process in which the sheetis not completely filled the saturant is applied to the face beforeprinting in amounts of from 35% to In any event the amounts of materialsintroduced into the sheet during the first step of partially saturatingfrom the face printing and applying saturant to the back, shouldconstitute at least 77% by weight of all filling materials in thefinished product. The finished product should have a non-fibrous tofibrous ratio by volume not lower than 2.8:1.0 and the preferred ratiois in the range of 3.2:1.0 and 3.5:1.0.

When following the procedure given in Example I, the saturant is appliedto the face of the sheet in an amount which, after removal of solvent,reduces the initial saturating capacity about 45%. After the printingstep the saturating capacity is reduced 74%.

The application of the saturant as described herein in substantialamount to the face, and to the face only, of the porous sheet beforeprinting results in the most satisfactory penetration of the printingand produces a sheet having the best working properties on the printingmachine. The application of the saturant from the back after printingtends to push the print or design toward the surface and markedlyimproves the brightness of the coloring of the face without impairingthe definiteness of the design. Our method of manufacture also gives aproduct of excellent sanding properties.

A particular advantage of our invention illustrated by the embodiment inthe first six examples is the production of a substantially filled sheetcarrying a pattern well through the sheet in a single continuousoperation. Subsequent processing involves simply the surface finishingsteps, further application of saturant to fill the sheet and additionaltime-consuming curing steps are avoided. Another advantage is theexcellent brightness of colors and definition of design that areobtained in the practice of the process. Another advantage is the shortperiod required for the production of the product. In addition, theproduct has advantages in its quality as a result of the types andproperties of the materials used in its production.

The product of the present invention is especially useful for floorcoverings. It also has many similar uses such as wall coverings and forthis purpose the sheets processed are somewhat thinner than in the caseof the floor covermgs.

As many apparently widely different embodiments of this invention may bemade without departing from the. spirit and scope thereof, it is to beunderstood that we do not limit ourselves to the specific embodimentsthereof except as defined in the appended claims.

We claim:

1. In a process for making floor coverings and the like the applicationto forwardly moving sheet material the successive steps which comprisepartially saturating absorbent paper felt sheet material by applyingsaturant containing solvent in amount not more than about 35% by volumeto the face only of said sheet material, then while the saturant isstill liquid printing without intermediate curing the sheet materialfrom the face with print paint which penetrates substan tially throughthe sheet, and subjecting the printed and saturant-containing materialto a temperature sufficiently elevated for the curing of said material,said absorbent sheet material being saturated by said saturant and printpaintat the curing stage in such amount that a substantially filledsheet is produced.

2. A process for making floor coverings which comprises applying toforwardly moving sheet material the successive steps of partiallysaturating absorbent paper felt sheet material by applying saturantcontaining solvent in amount not more than about 35% by volume to theface only of said material, immediately while the saturant is stillliquid, printing the sheet material from the face with print paint,applying saturant to the back of the printed material to push the printtoward the surface, and subjecting the printed saturant-containingmaterial to a temperature sufiiciently elevated for the curing of saidmaterial, said absorbent sheet material being saturated by the facesaturant, print paint, and back saturant at the curing stage in suchamount that a substantially filled sheet is produced.

3. A process for making floor coverings which comprises applying toforwardly moving sheet material the successive steps of partiallysaturating absorbent paper felt sheet material by applying saturantcontaining solvent in amount not more than about 35% by volume to theface only of said material, immediately while the saturant is stillliquid, printing the sheet material from the face with print paint,applying saturant tothe back and of said material, partially curing theprinted and saturated sheet material at elevated temperature, pressingthe material, and completing the cure, said absorbent sheetmaterialbeing saturated by said saturant and print paint at the curingstage in such amount that a substantially filled sheet is produced.

4. A process for making floor coverings which comprises applying toforwardly moving sheet material the steps of partially saturatingabsorbent paper felt sheet material by applying saturant containingsolvent in amount not more than about 35% by volume to the face only ofsaid material while the saturant is still liquid, printing the sheetmaterial from the face with print paint, partially curing at elevatedtemperature, completing the saturation of the sheet material, furthercuring at elevated temperature, pressing to impart a smooth even surfaceto the sheet material and completing the cure at elevated temperature,said absorbent sheet material being saturated by said saturant and printpaint at the curing stage in such amount that a substantially filledsheet is produced.

5. A process for making floor coverings which comprises applying toforwardly moving sheet material the steps of partically saturatingabsorbent paper felt sheet material by applying saturant containingsolvent in amount not more than about 35% by volume to the face only ofsaid material immediately while the saturant is still liquid, printingthe sheet material from the face with print paint, applying saturant tothe back of said material, partially curing at elevated temperature,completing the saturation of the sheet material, further curing atelevated temperature, pressing to impart a smooth even surface to thesheet material and completing the cure at elevated temperature, saidabsorbent sheet material being saturated by the'face saturant, printpaint, and back saturant at the curing stage in such amount that asubstantially filled sheet is produced. I

6. The process set forth in claim 1 inwhich the sheet material issaturated from the face in an the initial saturating capacity of thesheet and in which the saturant is a pigmented low body drying oil-resinvarnish, and in which said print paint is a high viscosity paint of lowsolvent content applied in an amount oi from 20% to by volume of theinitial saturating capacity of the sheet.

'7. The process set forth in claim 1 in which the sheet material is anabsorbent paper felt having a kerosene absorption 01' 250-320% and aporosity of 1.8 to 2.2 seconds and in which the sheet material issaturated from the face in an amount of to by'volume of the initialsaturat ing capacity 01' the sheet with a pigmented low body dryingoil-resin varnish of low solvent content and in which said print paintis a high viscosity paint of low solvent content applied in an amount offrom 20% to 30% by volume of the initial saturating capacity of thesheet.

LOUIS LEONARD LARSON. GEORGE LEWIS SCHWARTZ.

amount of not less than about 35% by volume of"

